Rotary vapor generator



July 12, 1966 J. H. ANDERSON 3,260,050

ROTARY VAPOR GENERATOR Filed Oct. 12, 1964 4 Sheets-Sheet l INVENTOR.JAMES H. ANDERSON BYKM WJLQW iv M A TTORNE Ys.

July 12, 1966 J. H. ANDERSON ROTARY VAPOR GENERATOR 4 Sheets-Sheet 2Filed Oct. 12, 1964 FIG. 2

INVENTOR JAMES H ANDERSON BY/ flh /L.u+

. nlllikllllllllll ATTORNEYS,

July 12, 1966 J. H. ANDERSON 3,260,050

ROTARY VAPOR GENERATOR Filed Oct. 12, 1964 4 Sheets-Sheet 3 FIG. 5

' INVENTOR.

JAMES H. ANDERSON Y a B 654 ATTORNEYS J. H. ANDERSON ROTARY VAPORGENERATOR July 12, 1 966 4 Sheets-Sheet 4 Filed Oct. 12, 1964 INVENTOR.

JAMES H. ANDERSON BY j M 2 m A TTORNEY'.

United States Patent 3,260,050 ROTARY VAPOR GENERATOR James H. Anderson,1615 Hillock Lane, York, Pa. Filed Oct. 12, 1964, Ser. No. 402,993 19Claims. (Cl. 60-39.18)

This invention relates generally to vapor generators and moreparticularly to vapor generators having a rotating vapor tube systemtherein.

Although the vapor generator of this invention may be used with varioustypes of boiling liquids for many suitable purposes, it is specificallyintended that this boiler be incorporated in the automotive power plantsystem disclosed in applicants co-pending application, Serial No.373,661, filed June 9, 1964. As disclosed in that application, therotary or rotating vapor tube boiler is particularly suitable for usewith a closed cycle halocarbon vapor system acting as a power source formotor vehicles. The rotary feature enables the provision of alightweight, minimum size boiler in a vehicle, the boiler beingparticularly suited for utilizing a halocarbon as the boiling liquidsince the rotary vapor tube system diminishes the likelihood of hotspots in the vapor tubes thereof. Such hot spots degenerate thehalocarbons making them unfeasible for use in the closed circuit systemcontemplated in the abovementioned co-pending application.

It is an object of this invention to provide an improved rotary vaporgenerator particularly adapted for incorporation in a vehicular primemover system.

It is another object of this invention to provide a vapor generatorwhich is light in weight and of minimum size.

It is a further object of this invention to provide a highly efficientrotary vapor generator incorporating a preheater, heater and superheaterin the same basic structure.

It is still another object of this invention to provide a rotary vaporgenerator which requires a minimum percentage of high temperaturematerial in the structure thereof by providing a burner chamber thereforwhich is fully shielded by liquid containing structure.

It is still a further object of this invention to provide a vaporgenerator which is particularly adapted to work with halocarbons byincorporating a rotating vapor tube structure therein to minimize theprobability of vapor pockets and attendant halocarbon degenerating hotspots in the vapor tube structure thereof.

It is yet another object of this invention to provide a small compactvapor generator particularly adapted for use in prime mover systems byobtaining a high heat transfer rate between the vapor tubes of thegenerator and the heating gases through the incorporation of a rotaryvapor tube structure therein.

It is yet a further object of this invention to provide a vaporgenerator which may be economically perpetually maintained at operatingpressure by enclosing the vapor generator structure in a low heattransfer insulation medium and by providing internal and insulatedvalving to avoid leakage of the vapor phase from the generator duringshut-down periods thereof.

These and other objects of the invention will be apparent to thoseskilled in the art when reference is made to the following detaileddescription when viewed in light of the accompanying drawings whereinlike numerals indicate like parts throughout the figures thereof andwhere- FIGURE 1 is a schematic representation of a portion of a systemincorporating a boiler in accordance with the invention;

FIGURE 2 is an enlarged elevational view in section and partly brokenaway of a vapor generator in accordance with the invention;

3,250,050 Patented July 12, 1966 FIGURE 3 is an enlarged fragmentaryplan view, partly in section, of a portion of the structure of FIGURE 2;

FIGURE 4 is an enlarged fragmentary view in section of another portionof the structure of FIGURE 2;

FIGURE 5 is an enlarged fragmentary elevational view in section of yetanother portion of the structure of FIG- URE 2 showing the bearing andseal portion thereof;

FIGURE 6 is an elevational fragmentary view in section of still anotherportion of the structure of FIGURE 2;

FIGURE 7 is a sectional view of the structure view of FIGURE 6 takenalong the lines 7-7 thereof;

FIGURE 8 is a fragmentary elevational view in section of still anotherportion of the structure of FIGURE 2 showing details of a fluid controlmechanism therefore;

FIGURE 9 is a fragmentary elevational view in section of a portion ofthe insulating wall of the boiler of FIG- URE 2;

FIGURE 10 is a sectional view taken along the lines 10-10 of FIGURE 8;

FIGURE 11 is a view similar to FIGURE 1 showing a variation in thesupply system of a boiler in accordance with the invention.

Referring now to FIGURE 1 of the drawings, a boiler, illustratedgenerally at 10, is shown incorporated in a power plant system. Theboiling fluid of the system is supplied through a fluid intake line 12and is exhausted, in a vapor state, through an output line 14 connectedto a standpipe 15 which is, in turn, centrally disposed in the boiler.The vapor from the output line 14 is then conducted to a turbine 16 orany other motor which can utilize vapor for converting thethermal-pressure energy thereof into mechanical or electrical energy.Fuel is supplied to the boiler system through the fuel input line 17 andexhaust is expelled therefrom through an exhaust line 18. The boiler,being of the rotary or rotating vapor tube type, requires power torotate the vapor tube structure thereof. This power is supplied at leastpartially by a motor 20 driving a vapor tube pulley 22 through a drivebelt 24. For a more detailed description of a system in which the boilermay be used, reference is again made to the aforementioned co-pendingapplication, Serial No. 373,661.

Turning now to FIGURE 2 of the drawings, an enlarged, detailed view ofthe boiler of FIGURE 1 is shown in section to enable the description andclear illustration of the internal components thereof. An annular flange26 comprises the main outer support for the boiler system. An innersupport plate 28 is bonded to the flange 26 through a heat insulatingring 30 disposed therebetween. The plate 28 supports a bearing base androtor support 32 through which the fluid input line 12 and the standpipe15 pass. A ball bearing housing 34 is mounted on the support 32 androtatably supports a boiler rotor 36 and a vapor tube support 39 throughball bearings 38. A vapor pressure dome 40 is centrally mounted on thesupport disc 39 and is connected, at the top thereof, to the vapor tubepulley 22 through a flexible splined shaft 42. Through theaforedescribed structure, the rotative power from the motor 20(FIGURE 1) is supplied to the support disc 39 and the rotor 36.

A double wall insulating shell shown generally at 44 is mounted on theflange 26 and support plate 28 and comprises an inner wall 46 and anouter corrugated wall 48 straddling the insulation 30 and configured tocompletely enclose the boiler structure therein. The space between thewalls of the shells is preferably evacuated and sealed to provide a lowheat transfer rate between the inner and outer surface thereof. In lieuof the evacuated space or in addition thereto, a filler having low heattransfer properties 49 (FIGURE .9) may be disposed between the walls 46and 43. This filler may be any suitable material such as glass fiber,iperlite, Styrofoam or the like. In addition to the evacuated shell 44,a base member 50 is attached beneath the main flange 26 and the supportplate 28 to define a space beneath these members, the space beingevacuated, sealed and/ or filled in the manner of the walls of the shellto provide minimum heat transfer between the support plate 28 and theatmosphere. An annular reinforcing flange 52 is disposed on the top ofthe shell 44 proximate the center thereof to provide support for theshaft 42 through a ball bearing housing and assembly 54. The top of theshell 44 is configured, at the point where the shaft 42 is disposedtherethrough, to form a depending annular chamber with an annular basedisposed proximate the bottom portion of the shaft 42. The configurationof the shell at this point provides isolation of the bearing housing andassembly from the interior of the boiler to prevent overheating thereofas well as heat transfer to the atmosphere therethrough. A bearingcooling and lubricating fluid is supplied to the bearing housing 54through a port 56 in the top end of the shaft 42 and is exhausted fromthe housing through a port 58 disposed beneath a pulley 22. This fluidmay be diverted from the boiler working fluid as is described in moredetail in applications above-mentioned co-pending application, SerialNo. 373,661.

Referring again to the vapor tube support 39, the support is providedwith an upstanding wall 60 around the outer periphery thereof forming,with the support, a general ly tub-shaped structure as shown. Acontinuous set of vapor tube coils are helically wound in the manner ofa multiple thread screw around the outside of the wall 60 to provide anouter bank of vapor tubes 62. The tubes are then helically wound downthe inner surface of the wall 60 to provide an inner bank of vapor tubes64. A plurality of U-shaped superheater coils 66 are mounted in anannular configuration between the wall 60 and the vapor dome 40. Thesuperheater coils are mechanically supported by a plurality of annularfins 68 in such a manner that an inner concentrically disposedforaminous tub is formed within the wall 60.

Referring again to the inlet line 12, an inlet fluid distribution line70 is communicative therewith and conmeets the inlet line to a preheaterinlet line 72. The line 72, drilled through a conical annular preheattube supsort 73, is connected to a continuous coil of tubing 74 which ishelically wound to form a cylinder proximate lo the inner wall 46 of theshell 44. The coil 74 thereby :orms a preheat she'll spaced from theinner wall 46 erminating in a connection with a preheat fluid collectornanifold 76 at the top thereof. The manifold, in turn, s connected tothe preheat fluid discharge line 78 which s routed down the outside ofthe shell formed by the rreheat coil 74 and through the connector 80 tothe aniulair space 82 situated within the bearing base 32. The tandpipe15 is coaxially supported within the annular pace 82 in spaced relationto the walls thereof by ribs i4 so that fluid in this space completelysurrounds the tandpipe. The annular space 82 is communicative, lroximatethe upper end thereof, with radially extending 'apor tube feed lines 86radially disposed in the vapor ube support 39. Each of the feed lines 86terminates 1 communication with an individual coil in the outer ank ofvapor tubes 62 at the outer ends thereof. As has een set forth above,the inner bank of vapor tubes 64 onstitute continuations of a set ofcontinuous vapor tubes I-hich cross over the wall 60 from the outer bankof tubes 2. The tubes of the inner bank terminate in a connecon tosuperheater feed conduit 88, disposed in the vapor lbe support 39 abovethe vapor tube feed lines 86. The iperheater feed conduits communicatewith the supereater coils 66, with communication being first made to reinnermost leg thereof and exhaust being made from it; outermost leg, Theoutermost leg of the superheater coil communicates, at the bottom endthereof, with the vapor dome feed line 90.

A vapor outlet valve, shown generally at 92 is centrally disposed on thetop end of the standpipe 15. This valve consists of a cylinder 94containing a piston 96 which has a valving member 98 formed integrallytherewith. The valving member cooperates with a valve .seat 100, mountedon the standpipe 15 to control communication between the vapor dome 40and the standpipe. The upper end of the cylinder 94 is partially sealedby a concave plate 102 to enable a certain amount of fluid leakage fromthe interior of the vapor dome 40 into the cylinder. A pilot line 104communicates with the enclosed space formed between the plate 102 andthe piston 86 for purposes to be described below.

Referring now to FIGURE 3 of the drawings, the disposition andcommunication of a portion of the various feed lines described above isshown in plan form. One of the vapor tube feed lines 86 is shownemanating from the annular space 82 for connection with one of the coilsof the outer bank of vapor tubes 62 mounted on the outer periphery ofthe wall 60. Return from the coil in the inner bank of vapor tubes 64 isaccomplished through the superheater feed line 88 which communicateswith the innermost leg of the superheater coil 66. The output from theoutermost leg of the coil 66 is discharged into the vapor dome feed linewhich communicates with the steam dome 40.

Referring to FIGURE 4, details of the superheater coils 66 are shown inplan form. As can be seen by reference to this figure, the superheatercoils are preferably elliptical in cross sectional shape with the majoraxis thereof oriented in a direction angled outwardly and toward thedirection of rotation of the boiler rotor as indicated by the solidarrow in that figure.

-In the operation of the device as thus far described and againreferring to FIGURE 2 of the drawings, fuel is supplied to the boilerthrough the fuel input line 17 and ignited by suitable means (not shown)so that a hot flame is injected into the lower portion of the boiler.The hot gases, rising in the direction shown by the broken arrows, passbetween the preheater coils 74 and the outer bank of vapor tube coils62, over the top of the wall 60 into the space formed therein. From thispoint the gases pass over the inner bank of vapor tubes 64 and throughthe structure formed by the superheater coils 66 and the fins 68. Theresultant gases, with most of the energy removed therefrom by passagethrough the aforementioned structures, are then exhausted outwardlyalong the inner wall 46 passing between the inner wall and the preheatercoils to the exhaust line 18. An annular seal 67, provided around theupper portion of the structure formed by the superheater tubes 66 andthe tins 68, is in close proximity with the preheater collector manifoldaround the inner periphery thereof and serves to direct all of theexhaust gases from the superheater coils directly to the boiler exhaust.Circulation of the gases may be augmented by furnishing a series of fanblades 108 on the base of the vapor tube support 39. These blades rotatewith the boiler rotor and are disposed to create upward currents betweenthe wall 60 and the preheater coil 74.

The fluid circuit Fluid from the intake line 12 is transmitted to thepreheater coils 74 through the distribution line 70 and the preheaterinlet line 72. The fluid is then circulated through the preheater coils74 picking up energy from the hot inlet gases rising between thepreheater coil and the outer bank of vapor tube coils 62. The preheatedfluid is then gathered in the preheater collector manifold 76 and passedthrough the preheater discharge 78 to the annular chamber 82. With theboiler rotor 36 and vapor tube support 39 suitably driven by the motor20 (FIG- URE 1), the fluid in the chamber 82, under the influence of thecentrifugal force generated by the rotating struc-.

ture, is passed through the vapor tube feed lines 86 to the outer bankof vapor tubes 62. Fluid is then circulated through the outer bank ofthe vapor tubes 62 where it is heated by the incoming gases risingbetween the preheater tubes 74 and the outer tube bank 62. Sincecentrifugal force is greatest at this point, the pressure acting on thefluid is at its highest value and, even though vapor may exist inisolated pockets in the fluid, the more .dense liquid phase of the fluidis kept at the outer surface of the bank with the less dense vapor beingforced to the inner surface of the tubing so that the liquid is alwaysdisposed next to the hottest part of the combustion chamber formedbetween the tubes. Local pockets of vapor which could cause hot spotsare thereby prevented by the rotating rotary structure of the boiler.The peripheral speed of the boiler rotor 36 is also greatest at thispoint thereby providing the highest heat transfer rates between the hotgases and the surface of the vapor tubes since heat transfer isproportional to the velocity of the gas over the surface to which heatis being transferred. The fluid is then passed over the top of the wall60 and down the inner bank of vapor tubes 64 where, because of the lowerpressure in this area and due to the incre-ased'fluid temperature, theliquid is transformed into vapor. The vapor then enters the superheaterfeed conduits 88 and is transferred to the super-heater coils 66. Thefluid circulating in these coils is then superheated by the hot gasespassing through the coils 66 and tins 68. As pointed out above, thefluid enters the inner leg of the superheater coils first and isexhausted from the outer leg so that a counterflow heat exchange efifectis produeed increasing the efficiency of heat transfer between thecombustion gases and the vapor in the tubes. This counterflow isachieved by passing the cooler input vapors through the cooler exhaustgases first and then exposing the warmer output vapors to the hotterinput gases thereby providing a maximum temperature differential and,therefore, the most efiicient heat exchange vbetween the gases and thevapor. From the superheater coils fluid is then transferred to the vapordome 40 through the vapor dome feed conduits 90 where it is collected inthe high pressure reservoir for-med thereby.

The valve 92, when initially disposed in a closed condition as shown, isheld in the closed condition by high pressure vapor which leaks throughthe seal for the plate 102 and exerts force between the plate and thepiston 96 to maintain the piston and the valving member 98 biasedagainst the valve seat 100. When vapor is required from the boiler, ableed valve 105 disposed outside of the boiler area in the pilot line104, is opened to exhaust the high pressure vapor from between the plate102 and the piston 96. The fluid pressure of the vapor in the dome,acting on the outer transverse surfaces of the piston 96, forces thepiston upwardly thereby lifting the valving member 98 from the valveseat 100 and allowing the high pressure, high temperature vapor to beexhausted through the output line 14. Referring again to the superheatertubes 66 and particularly to the view thereof shown in FIGURE 4, theelliptical configuration of these tubes and their disposition withrespect to the incoming gas offers a minimum amount of resistance to theflow of the combustion gas therethrough and, in combination with therotation of the structure as a whole, can be designed to further inducethe gas flow therethrough.

Although two circular rows of superheater tubes are shown, it should beunderstood that more than this number could be incorporated in thesuperheater structure if necessary. The particular shape of these vaportubes shown, although preferred for the reasons given above, could alsobe obviously varied without altering the basic operation of theinvention.

The helical arrangement of the vapor tubes in the banks 62 and 64, asbefore described, is like the configuration of a multiple thread screw.Each of the tubes may have more than one turn around the boiler rotordepending on 6 the tube size, fluid flow velocity, etc. The total crosssectional area of .the tube must be great enough to allow moderate fluidvelocity through the tubes as can be determined by proper designthereof.

It is particularly important and preferred that the valve 92 be locatedinside the vapor storage space and not outside of the boiler on the line14 since, if so situated, the valve would not be well insulated andwould, therefore, cool to a temperature lower than that of the vapordome on shut-down. The vapor .trapped in the valve at shutdown wouldeventually condense into liquid in the outlet line causing not only aheat loss but would throw a slug of liquid through the power system whenthe valve ultimately is opened.

It should be also obvious that the areas of the piston and valve seatcan be adjusted through standard design techniques and that springscould also be incorporated in the valve structure to alter or balancethe force acting on the valve as desired.

Since a fluid in the vapor state has a higher specific volume than fluidin the liquid state, a larger flow rate will be induced in the inwardlyflowing vapor conduits 90, than in the outwardly flowing liquid in theconduits 86. This situation can create an appreciable discharge velocitythrough the conduits 90, and this velocity may be utilized to helpprovide motive force for the rotor 36, thereby reducing the powerrequirements for rotation of the rotary stmcture through the shaft 42.Turning now to FIGURES 6 and 7 of the drawings, a device for soutilizing this increased vapor discharge velocity is shown. Generallyspeaking, the invention consists of means to deflect the exhaust flow,into the vapor dome 40, in a direction opposite to the direction ofrotation of the boiler rotor thereby utilizing the jet reaction force ofthe exhausting vapor to aid in the rotation of the boiler rotor. This isachieved by providing a ring of exhaust nozzles 112 around the innerperiphery of the boiler rotor 36 adjacent each of the vapor dome feedconduits 90, the exhaust nozzles being formed to deflect the exhaustfrom these conduits in a direction opposite the rotative direction ofthe rotor indicated by the arrow.

Since both the rotor 36 and the stationary bearing base and the rotorsupport contain fluid, a seal must be provided to retain the liquidwithin the structure at the joint between the relatively rotating parts.Turning now to FIGURE 5, an enlarged detail of the main rotor seal isshown generally at 114. This seal incorporates principles more fullydisclosed in the applicants co-pending application, Serial No. 403,234,filed October 12, 1964, and generally includes rotating metallic sealface 116 mounted on the boiler rotor in close, lapped mechanical rubbingcontact with a stationary graphite seal face 118 mounted on the bearingbase and rotor support 32. The seal 118 is held against the seal 116 bya coil spring 120 and both seals are slightly free to align themselvesagainst each other by a loose mounting .to their supporting structureand flexible packing rings 122 and 124 providing sealing contact betweenthe seal member and the supporting structure. The contact portion of therubbing seal face is at approximately the same diameter as .thecylindrical surfaces on which the seal rings are mounted so thatunbalanced pressure from inside the seal faces produce very littlevertical or axial force on the rings. A chamber 126 is provided aroundthe seals 116 and 118 and is further pressurized with a lubricantthrough conduit 128 from a pressure source (not shown), the pressurethereof being kept approximately equal to the pressure of the fluid inthe space 82 so that the tendency of the fluid :to leak across thesealing faces under the influence of differential pressure is minimized.

The lubricant is sealed in the chamber 126 by a secondary seal which iscomposed of a graphite sealing ring 130 rotating against a stationaryspring biased seal face 132. A chamber 134 is provided around .theselatter-mentioned sealing members and is isolated by a packing seal 136.

This chamber is at approximately atmospheric pressure but is kept fullof liquid by the packing seal 136. As the lubricant tends to leak fromthe high pressure area of the chamber 126 into the low pressure 134, thelubricant collects in the chamber 134 and overflows through a passage138 into the area of the ball bearings 38 and from there may be drainedout to a lubricant sump (not shown). It should be obvious thatadditional lubricant for cooling and lubricating the bearings could besupplied from pumps (not shown) to .the chamber 134 if additionalcooling is required in the ball bearing area. A heat shield 140 isdisposed on the outside of the bearing housing to reduce the heattransfer from the combustion space inside of the boiler into the bearinghousing 34.

It is important to keep the seal rubbing speed and the diameter of theseal faces 116 and 118 as small as possible to minimize wear. To producethe minimum diameter in the seals, the standpipe is formed in the shapeof a venturi as shown with the throat of the venturi being near theposition of the seals with the diffuser toward the larger diameter atthe base of the standpipe. This provides a relatively small diameter andhigh velocity vapor flow at the throat of the venturi proximate theseals, however, the vapor kinetic energy is largely recovered andconverted into pressure by the expansion into the diffuser toward theoutlet of the standpipe.

By utilizing the centrifugal force, the conduits 86 can serve as apartial boiler feed pump to increase the pressure of the fluid thereinto a higher value. The tubes may be modified so that the passages inthemselves do not generate any substantial pressure increase byalternately connecting conduits 88 (FIGURE l) and 86. If, however, it isdesired to utilize the conduits 86 as partial feed pumps, then theinterior of the vapor dome 40 (FIGURE 2) must be sealed from the annularspace 82 since a pressure differential will exist therebetween. InFIGURE 5, this seal is shown generally at 142 and comprises closefitting sealing rings 144, 145, 146 and 147 which are mounted on therotor 36 and run with a close clearance around the standpipe 15.

Referring again to FIGURE 2, a safety pressure release device 148 isdisposed in the annulus between the bearing base and rotor support 32and the standpipe 15. This device is required on high pressure boilersand comprises a breakable disc of carbon or other suitable brittlematerial. The disc is supported at the outer periphery thereof bysuitably soft gaskets 150 and 152 and is sealed against the standpipewall by an O ring 154 or other suitable packing material.

In case of an overpressure condition in the boiler, the disc willfracture and release the boiler fluid downward, thereby serving as anemergency pressure release. Under the normal conditions the disc isbeneath the fluid in the liquid state and is not subject to the highersuperheat temperature except at the surface of the output line 14. Thedisc furthermore, is not subjected to the full pressure of the fluid innormal operation because of the centrifugal force on the liquid, but inthe event of overheating with the attendant overpressure in the boiler,the vapor will tend to reverse flow and fail the disc. The location ofthe disc also provides for easy replacement thereof in the event ofoverheating of the boiler or premature fatigue failure. It should benoted that the disc is under full fluid pressure when the boiler is shutdown and not rotating, thereby providing for safety release at the mostdangerous time when overpressure is likely to occur since overheating ismost likely through control malfunction when no one is normally inattendance.

It should be noted that, in general, the boiler provides gas-to-fluidcontact in such a manner that the hottest exhaust gas generally gives upheat to the coolest vapor passages, thereby providing the greatesttemperature differential and the greatest possible heat transfer fromthe exhaust gases. The arrangement and configuration of the vapor tubesalso provides insulation for the boiler inner wall 46 so that hightemperature materials are not required for this portion of the boilerstructure.

As an alternate to having fan blades 1118 on the rotor 36, an externalfan 183 (FIGURE 11) can be used to force air through the combustionspace. Guide fins could be placed on the preheat inlet line 72 to guidethe combustion gases radially outwardly. This variation would use lesspower since less power is required to move the cool air than the hotcombustion gases and the relative velocity of the rotating vapor tubeswith respect to the gas would, therefore, be higher. If an external fanis used, it is also possible to form the fan blades 108 in aconfiguration so that they would act as turbine blades and utilizing theaction of the flow through the blades to turn the rotor. This would, ineffect, produce a simple combustion gas turbine which would make itpossible to turn the rotor with a minimum requirement for externalpower.

Referring to FIGURE 8 and FIGURE 11, an arrangement is shownincorporating the above-referred to external fan, turbine blades 108aand also incorporating turbine nozzles 184 mounted on the disc 73 whichencloses the preheat inlet lines 72. This arrangement directs theincoming flow of gas against the turbine blades 108a. In effect, withthis arrangement, the rotor 39 becomes a gas turbine with sufiicientpower to overcome friction and whatever boiler feed pumping powerrequired by the rotor. By utilizing this arrangement, the motor forturning the rotor can be comparatively small and need only be used atstartup and possibly at idling conditions.

The space defined by the outer wall 48 and the inner wall 46 ispreferably evacuated and/or filled with an insulation material therebyproviding an extremely effec tive heat transfer barrier around theentire boiler structure. Little heat loss, therefore, occurs in theboiler and, as described in greater detail in the aforementionedcopending application, Serial No. 373,661, allows the boiler to be shutdown for long periods of time while maintaining operating pressure witha minimal expenditure of fuel.

It should be noted that, as shown in FIGURE 2, the gas inlet and exhaustoutlet openings are disposed toward the lower portion of the boiler.This provides a benefit in that, since the hotter air and gas normallytends to rise to the top of the confine, the heat losses through theseopenings when the boiler is in a period of extended shutdown will bekept to a minimum. It is also contemplated that valves may be insertedin the exhaust and/or intake lines outside of the boiler to providereduced heat loss. This system is more completely described in theaforementioned co-pending application, Serial No. 373,661.

The outer wall 48 is subjected to compressive stress and is, therefore,preferably formed with integral corrugations to resist collapse of thewall under the force imposed by the vacuum. The outer wall 48 is keptconcentric with the inner wall 46 preferably by utilizing a low heattransfer type of spacing support therebetween. A support ideally adaptedfor this use is described in detail in applicants co-pendingapplication, Serial No. 374,448, filed June 11, 1964.

In a rotary boiler such as that described above, and particularly in arotary boiler utilizing halocarbon as a boiling liquid, the maintenanceof the proper amount of liquid in the boiler during operation thereofconstitutes an important problem. It is very important to keep theboiling fluid in its liquid form on the outer periphery of the rotatingsection and particularly in the outer portion of the outer bank of vaportubes 62 because this structure is closest to the hottest part of thecombustion zone. It is also important to restrict the fluid in thesuperheater section to the vapor phase in order to raise the temperaturethereof high enough to obtain the proper thermodynamic cycle efficiency.The line of demarkation between the liquid and the vapor phase should,therefore,

-or decreased liquid'flow to the boiler as required.

.sulation ring 178.

be near the outer periphery of the rotor 36, between the superheatertubes 66 and the outer bank of vapor tubes 62. Referring now to FIGURE 8of the drawings, a device for providing a proper control for the fluidflow to the'boiler and, therefore, the position of the vapor-liquidphase interface is shown. The flow of liquid into the boiler can beeasily cont-rolled by a throttle valve at the feed pump and any type ofservo motor could operate the valve in response to a suitable signalfrom a sensing device in the boiler. The main difficulty in the controlof the phase interface line is the problem of continually Sensing thelocation of the line. It is, therefore, necessary to provide a devicewhich signals a servo motor or the like-to operate the throttle valveand provide increased In the device of FIGURE 8, a channel 156isprovided radially in the boiler rotor 36between adjacent vapor tube feedlines 86 (FIGURE 2) and is in communication with the inner bank of thevapor tubes 64 through a sensing bore 158. A mass bob 160 is suspendedin the channel 156 by a cable or rod 162 which, in turn, is connected toa spring 164 mounted on a support 166 situated on the rotor 36. Acontact 168 is disposed on the free end of the spring 164 and co-acts'with a similar contact 170 mounted on an annular slip ring 172. The slipring 172 is supported on the rotor 39 by a suitable insulation ring 174and is contacted by a carbon brush 176, mounted on the valve seat 100and insulated therefrom by an in- The brush is connected to a feed pumpvalve servo motor 179 by an insulated electrical conductor 180 disposedthrough the wall of the valve seat 100, enclosed by a thermallyinsulated tube 182 to the exterior of the boiler.

In operation, the sensing device functions as follows: When the boileris in operation and the rotor 36 is rotating, the liquid-vapor interfaceof the fluid in the vapor tubes takes a position of equilibrium, withrespect to the fluid in the centrifugal force field, in the channel 156through the agency of the sensing bore 158. When the boiler is at aproper rotative speed, the mass bob 160 is suspended concentricallywithin the channel 156 and exerts a force on the spring 164 through thecable 162. The force exerted by the mass bob is proportional to thesquare of the rotational velocity of the rotary portion of the boilertimes the mass of the bob less the mass of the fluid 'which the bobdisplaces. Since the density of liquid is greater than that of vapor,the force will be less when the mass is immersed in liquid than when itis immersed in vapor. For example, if the density of the material of themass bob 160 is equal to that of the liquid, then the force on the cablewould be substantially zero if the mass is fully immersed in the liquid.As the line of demarcation or interface between the liquid and the gasmoves along the length of the mass bob 160, the force on the cable 162will change and this change can be utilized to deflect the spring. Whenthe liquid in the channel 156 is reduced to a certain extent, theeffective mass of the mass bob 160 acting on the spring 164 is increasedto a degree suflicient, under the influence of centrifugal force, todeflect the spring 164, thereby breaking the electrical circuit betweenthe contacts 168 and 170. This break in the circuit is sent as a signalto the control operating a valve 181 at the feed pump through the slipring 172, brush 176, and conductor 180 to open the-valve and providean'increasedamount of liquid to the boiler. When the amount of liquid inthe boiler is suflicient to maintain the desired vapor-liquid phasedistribution, the volume of fluid in 1 the channel 156 is increased tothe point that the eflective mass of the bob acting on the spring isovercome by the force of the spring and the contacts close completingthe trical transducers that could be utilized to transmit the signalindicating the sensed liquid-vapor phase line. Other devices such, forexample, as variable resistance rheostats operated by the movement ofthe spring 164, variable inductance devices comprising a magneticmembrane inside a coil, variable capacitance devices or the like couldobviously be used.

The slip ring and brush structure described could also be replaced witha small coil on the valve seat proximate a magnetic material mounted onthe spring 164 so that, as the magnetic material passes the coil on eachrevolution of the rotor, the inductance of the coil would be affected toa greater or lesser degree depending on the proximity of the magneticpiece 164 to the coil, which, in turn, would be controlled by thedeflection of the spring 164, thereby providing a signal for the amountof deflection of that spring. The change in force acting on the springcan be translated into a changing electrical signal by utilizing atransducer to sense the change in force. In the simplified case shown inFIGURE 8, the transducer is in the form of the switch shown whichconsists of the pair of contacts 168 and 170. The contact 168 isgrounded to the boiler and frame of the apparatus through the boilerstructure, ball bearings, etc. while the contact 170 is suitablyinsulated from the supporting structure.

As a further alternative, the sensing device for the vapor-liquidinterface could take the form of a temperature sensitive devicesuspended in the channel 156. If the device were submerged in liquid,then the temperature would be at or below the saturation temperature forthe fluid whereas if the sensing device were primarily in vapor, thetemperature would be closer to the superheat temperature for that vapor.The temperature sensitive device could be a thermistor, which has asharp change in resistance under the influence of a small change intemperature, which 'would change the current in a circuit in the samemanner as was accomplished by the variable resistance transduceractuated by a change of force as described above.

It is intended that an automatic control to monitor the fuel supply tothe boiler will be incorporated with the boiler system to providecontinuing control of the supply of heat to the boil as heat is takentherefrom. This control could be operated in various manners, such, forexample, as temperature sensitive probes in the vapor system to signalthe control for increased heat when the temperature level of the vapordiminishes or increases to a certain value.

Although the geometry and dimensions of the boiler system will depend onthe power requirements placed thereupon, a boiler of the type described,suitable for .powering the automotive vehicle of the above-referred toco-pending application Serial No. 373,661, could reasonably be on theorder of 24 inches in height by 24 inches in diameter. The vaporpressure anticipated in the system is in the neighborhood of 300 to 400lbs. per square inch maximum with a vapor temperature in theneighborhood of 400 F. The maximum temperature at the hottest parts ofthe burner section of the boiler is not anticipated to be greatly inexcess of 500 F. In the system described as intended to be used in theautomotive power plant, the rotating velocities for the boiler rotor androtating elements are not predicted to be greatly in excess of 2000r.p.m.

Although many fluids could be used as the boiling liquid in the abovesystem, it is specifically contemplated that a suitable halogenatedhydrocarbon such as one of the fluorocarbons will be utilized since theyare particularly suitable for use in this system. A preferred compoundof this type is octafluorocyclobutane (C 1 which has boiling point of21.1 F. at standard atmospheric pressure and is commercially availableunder the trademark name of Freon-C318. This fluid has, in relation towater, a higher vapor pressure, lower specific volume at atmosphericpressure and standard temperature, higher molecular weight, lower latentheat of vaporization and a lower energy drop per pound of fluid passingthrough an expansion cycle. This fluid although initially expensive, isparticularly suitable for the use contemplated since it allows the useof a small volume of fluid because of the high energy deliverycapability. A fluid capacity of 2 gallons is deemed feasible for thesystem described when applied to an average automotive power plant.

A particular advantage realized by the boiler embodying this inventionlies in the type of fuel usable in its operation. Any type of reasonablylight hydrocarbon fuel may be used interchangeably and the boiler willoperate efliciently on propane, butane, kerosenes, low octane, or highoctane gasoline, diesel oil, etc. The combustion in the boiler isefficient and relatively complete thereby substantially eliminatingdischarge of unburned residue such as carbon monoxide in the exhaustgases.

What has been set forth above is primarily intended as exemplary toenable those skilled in the art in the practice of the invention. Itshould, therefore, be understood that, within the scope of the appendedclaims, the invention may be practiced otherwise than as specificallyset forth.

What is, therefore, claimed as new and desired to be protected byLetters Patent of the United States is:

1. A vapor generator comprising:

a vapor generator enclosure having vaporizable fluid therein, a vaporexhaust standpipe disposed in said enclosure, means to control fluidcommunication between said enclosure and said standpipe, means to heatsaid enclosure to provide vaporization of the fluid therein, a rotatingsupport in said enclosure coaxially disposed intermediate the ends ofsaid standpipe, a vapor dome mounted on said rotating support to enclosethe upper end of said standpipe, a fluid heat exchange and transmittingtube assembly disposed on said rotating support, means to transmit vaporfrom said assembly to said vapor dome for storage therein, a preheatertube assembly fixedly mounted around the walls of said enclosureadjacent said rotating support and fluid tube assembly, means to supplyliquid to said preheater tube assembly for preheating therein and meansto transmit preheated liquid therefrom to the fluid tube assemblydisposed on said rotating support, and means to control the quantity ofliquid and heat supplied to said generator.

2. A vapor generator for vapor powered prime movers comprising:

a generator support;

a vertical vapor exhaust standpipe coaxially disposed through saidsupport, means to control communication into the upper end of saidstandpipe;

an enclosure mounted on said support to enclose the upper surfacethereof;

a rotating support mounted in said enclosure coaxially around saidstandpipe, means to rotate said rotating support;

a vapor dome coaxially mounted on said rotating support to enclose theupper end of said standpipe;

an annular stationary preheater support disposed around the periphery ofsaid rotating support;

and a fluid system comprising:

(a) a fixed preheater tube system including a helical coil forming avertical tubular structure mounted on said preheater support, means tosupply fluid to said preheater coil for preheating therein;

(b) an annular reservoir disposed around said standpipe, means to supplyfluid from said preheater coil to said reservoir;

() a plurality of helically wound vapor tube coils configured to form avertical tubular structure mounted around the periphery of said rotatingsupport to rotate therewith, means 'to supply fluid from said reservoirto said vapor tubes for vaporization therein;

((1) a plurality of superheater tubes disposed on said rotating supportintermediate said vapor tubes and said vapor dome, means to supply vaporfrom said vapor tubes to said superheater tubes for superheatingtherein, and means to transmit superheated vapor from said superheatertubes to said vapor dome for collection therein;

gas inlet and exhaust conduits through the walls of said enclosure, andmeans to supply heat through said inlet to said enclosure forcirculation between said preheater tubes and said vapor tubes, means todirect said gas inward over the top of said vapor tubes and through saidsuperheater tubes, and means to exhaust said gas between said preheatertubes and the walls of said enclosure to said exhaust.

3. A vapor generator comprising:

a base support;

a casing mounted on said support to form an enclosure therefor;

a vapor exhaust standpipe coaxially disposed through said support andextending into said enclosure, means disposed at the upper end of saidstandpipe to control communication therewith;

an annular wall concentrically disposed around a portion of saidstandpipe, said Wall with said standpipe defining a fluid reservoirtherebetween;

means to supply heated gas to and exhaust spent gas from said enclosure;

a rotating support in said enclosure coaxially disposed intermediate theends of said standpipe adjacent said reservoir, means to rotate saidrotating support;

sealing means between the annular wall defining said reservoir and saidrotating support;

a vapor dome coaxially mounted on said rotating support, said domeenclosing the upper end of said standa vapor tube assembly disposed onsaid rotating support proximate the periphery thereof, means to transmitliquid from said reservoir to said vapor tube assembly for vaporizationtherein;

a superheater tube assembly disposed on said rotating supportintermediate said vapor tube assembly and said vapor dome, means totransmit vapor from said vapor tube assembly to said superheaterassembly for superheating therein, and means to transmit superheatedvapor from said superheater assembly to said vapor dome for storagetherein;

an annular preheater support fixed with respect to said base support anddisposed around and proximate the periphery of said rotating support;

a preheater tube assembly disposed on said preheater support includingmeans to supply liquid thereto for preheating therein, and means totransmit preheated liquid from said preheater tube assembly to saidreservoir for collection therein;

and means to control the quantity of liquid supplied to said preheatertube assembly, said means being actuated by the location of thevapor-liquid interface between said vapor tube assembly and saidsuperheater tube assembly.

4. A vapor generator comprising:

a bas support;

a casing mounted on said support to form an enclosure therefor;

a vapor exhaust standpipe coaxially disposed in spaced relationshipthrough said base support, means disposed at the upper end of saidstandpipe to control communication therewith;

an annular wall concentrically disposed around a portion of saidstandpipe, said wall with said enclosure defining a fluid reservoirtherebetween;

a fiangeable safety disc disposed in sealing relationship between said"base support and said standpipe to form the lower portion of saidreservoir, said disc being configured to fail and provide safety releaseof vapor in said reservoir upon overpressure therein;

' means to supply heated gas to and exhaust spent gas from saidenclosure;

a rotating support in said enclosure coaxially disposed intermediate theends of said standpipe adjacent said I reservoir, means to rotate saidrotating support; sealing means between the annular wall defining saidreservoir and said rotating support;

a vapor dome coaxially mounted on said rotating support, said domeenclosing the upper end of said standp r a vapor tube assembly disposedon said rotating support proximat the periphery thereof, means totransmit liquid from said reservoir to said vapor tube assembly forvaporization therein;

a superheater tube assembly disposed on said rotating supportintermediate said vapor tube assembly and 'said vapor dome, means totransmit vapor from said vapor tube assembly to said superheaterassembly for superheating therein, and means to transmit superheatedvapor from said superheater assembly to said vapor dome for storagetherein, said superheater tubes being elliptical in cross section, themajor axis of said superheater being angled outwardly in the directionof rotation of said rotating support to provide miniinumresistancethereof to the flow of gas therethrough;

an annular preheater support fixed with respect to said base support anddisposed around and proximate the periphery of said rotating support;

a preheater tube assembly disposed on said preheater support includingmeans to supply liquid thereto for preheating therein, and means totransmit preheated liquid from said preheater tube assembly to saidreservoir for collection therein; 1

and means to control the quantity of liquid supplied to said preheatertube assembly, said means being actuated by the location of thevapor-liquid interface between said vapor tube assembly and saidsuperheater tube assembly.

5. A generator in accordance with claim 4 wherein said base supportincludes upper and lower spaced surfaces having thermal insulationtherebetween, and wherein said casing includes spaced outer and innerwalls thereto having thermal insulation therebetween.

6. A vapor generator in accordance with claim 5 wherein said thermalinsulation includes a material of low thermal conductivity between saidsurfaces and between said walls.

7. A vapor generator in accordance with claim 6 wherein said thermalinsulation further includes a vacuum between said surfaces and betweensaid walls.

8. A vapor generator in accordance with claim 5 wherein said thermalinsulation includes a vacuum between said surfaces and between saidwalls.

9. A generator in accordance with claim 4 wherein said sealing meanscomprises an annular non-rotating shoulder having a transverse surfacethereto coaxially mounted on said annular wall, said shoulder having acylindrical sealing surface therearound, an annular nonrotating sealingmember slidably and sealably mounted .on said sealing surface, arotating shoulder mounted on shoulder, an annular rotating sealingmember slidably and sealably mounted around said rotating shouldercylindrical sealing surface in abutting sealing relationship to saidnon-rotating member, the abutting faces of said members beingsubstantially equal in area and diameter to the transverse surfaces ofsaid shoulders, said annular wall having a bore coaxially disposedtherein defining a chamber around said shoulders and said sealingmembers, annular bearings coaxially disposed around said annular wall torotatably support said rotating support, means to provide communicationbetween said bearings and said chamber, means to supply lubricant underpressure to said bearings and said chamber, and means to substantiallyequalize the pressure between the lubricant in said chamber and thefluid in said reservoir to minimize pressure differentials across thesealing faces of said sealing members and means to bias said sealingmembers in sealing relation to one another.

10. A vapor generator in accordance with claim 4 wherein said means torotate said rotating support comprises at least a shaft coaxiallymounted on said rotating support and extending through said enclosure, amotor associated with said shaft to provide rotation thereof, and motorcontrol means to control the operation of said motor.

11. A vapor generator in accordance with claim 10 wherein said means torotate said rotary support further comprises turbine blades mountedthereon, said blades being disposed to be rotated by the heated gasessupplied to said enclosure to provide a portion of the energy forrotation of said rotating support. 7

12. A generator in accordance with claim 10 wherein said means to rotatesaid rotary support further comprises a gas compressor associated withsaid means to supply heated gas to said enclosure, said compressor beingdisposed to provide pressurization of said gas prior to heating thereof,turbine nozzles mounted on said preheater tube support adjacent saidrotating support, turbine blades mounted on said rotating supportadjacent said nozzles,

said blades and said nozzles extracting energy from the pressurizedheated gas supplied to said enclosure to provide rotative power for saidrotating support.

13. A vapor generator in accordance with claim 10 wherein said means torotate said rotating support further comprises flow nozzles disposed onsaid means to transrnit superheater vapor, said nozzles being configuredto deflect said vapor into said vapor dome in a direction opposite thedirection of rotation of said rotating support, whereby reaction fromthe deflected vapor flow through said nozzles provides a portion of theenergy for rotation of said rotating support.

14. A vapor generator in accordance with claim 4 wherein said means tocontrol communication with said standpipe comprises:

a valve seat concentrically disposed at the top ofsaid standpipe;

a valving member movable with respect to said seat between a closedposition engaging said seat blocking communication with said standpipeand an open position spaced from said seat and providing comrnunicationbetween said dome and said standpipe;

a cylinder coaxially disposed over said valve seat, said cylinder havinga closed end and open end thereto, said open end being disposed adjacentsaid valve seat;

a follower piston associated with said valviug member movable therewith,said piston having transverse areas on either side thereof, said pistonbeing slidably mounted in said cylinder and having a transverse areathereof exposed to the interior of said dome, said piston further havinga transverse area exposed to the interior of said cylinder greater thanthe transverse area thereof exposed to the interior of said dome,partial sealing means between said dome and said cylinder to provide acontrol leakage between the interior of said dome and said cylinder;

bleed means including a bleed valve disposed on the exterior of saidenclosure and communicative with the interior of said cylinder toprovide remote control of bleeding from the interior of said cylinder;

whereby closure of said bleed valve provides actuation of said pistonand said valving member to said closed position under the influence ofdifferential pressure for acting on said piston resulting from thepressure buildup in said cylinder through leakage thereto from saiddome, and whereby opening of said bleed valve will provide actuation ofsaid valving member to said open position under the influence of adifferential pressure acting on said piston resultmg from the drop inpressure in said cylinder through the loss of pressure therefrom throughsaid bleed valve.

15. A vapor generator in accordance with claim 4 wherein said means tocontrol the quantity of liquid supplied to said preheater tube assemblycomprises sensing means to signal the liquid-vapor interface between thevapor tubes and superheater tubes of said vapor generator, a vapor feedvalve to control the supply of liquid to said preheater tube assembly,operating means to operate said valve, and means to transmit the signalfrom said sensing means to said operating means to vary the quantity offluid supplied to said vapor generator as determined by the location ofsaid interface therein.

16. A vapor generator in accordance with claim 4 wherein said rotatingsupport has at least one radially disposed bore defining a chambertherein, said chamber being communicative with said vapor tube assembly,and wherein said sensing means comprises a mass bob axially disposed insaid chamber in spaced relationship to the walls thereof, an electricaltransducer, means connecting said mass bob to said transducer to providea signal of the force acting on said bob, said bob being disposed tointersect the vapor-liquid interface between the vapor tubes andsuperheater tubes in said vapor generator to thereby signal the locationsaid interface through said transducer as a function of the relativemass of said bob when said rotating support is rotating.

17. A vapor generator comprising:

an annular base support including upper and lower spaced surfaces,thermal insulation between said surfaces;

a casing mounted on said support to form an enclosure thereon, saidcasing including spaced outer and inner walls thereto, thermalinsulation between said walls;

a vapor exhaust standpipe coaxially disposed in spaced relation throughsaid support and extending into said enclosure, said standpipe having areduced Venturi portion thereto disposed intermediate the ends thereof,means disposed at the upper end of said standpipe to controlcommunication therewith;

an annular wall concentrically disposed around a portion of saidstandpipe, subjacent said reduced portion, said wall with said enclosuredefining a fluid reservoir therebetween;

a safety release including a flangeable safety disc disposed in sealingrelationship between said base sup port and said standpipe, said discbeing configured to fail and provide safety release of vapor in saidreservoir upon over pressure therein;

means to supply heated gas to and exhaust spent gas from saidenclosure;

a rotating support in said enclosure coaxially disposed intermediate theends of said standpipe adjacent said reservoir, means to rotate saidsupport;

sealing means between the annular wall defining said reservoir and saidrotating support, said sealing means being disposed adjacent the reducedportion of said standpipe;

a vapor dome coaxially mounted on said rotating support to enclose theupper end of said standpipe;

a plurality of helically wound vapor tube coils mounted around theperiphery of said rotary support, said coils being configured when woundto form a vertical tubular structure extending upwardly from said.rotary support an annular vapor tube support mounted on said rotarysupport, said vapor tube support being coextensive with and adapted tosupport the tubular structure formed by said vapor tubes, said rotarysupport having radially disposed bores therethrough connectingindividual ones of said vapor tube coils to said reservoir to transmitfluid from said reservoir thereto;

a plurality of superheater tubes disposed on said rotary supportintermediate said vapor tubes and said vapor dome, each of saidsuperheater tubes com-prising an inverted U-shaped coil having outer andinner legs thereto and extending upwardly perpendicular to said rotarysupport, said superheater tubes being disposed in spaced relationship ona radius around said rotating support to form an upstanding annularstructure thereon, a plurality of annular discs in coincidence with theannular structure formed by superheater tubes and disposed in spacedvertical relationship along the legs thereof, said discs engaging eachof said superheater tubes to provide structural support and heatexchange fins therefore, said rotating support further having radial-1ydisposed bores therein connecting each of said vapor tubes to an innerleg of said superheater tube for transmission of fluid from said vaportubes to said superheater tubes and a plurality of radially disposedbores therein connecting the outer leg of each of said superheater tubesto said vapor dome for transmission of fluid from said superheater tubesto said vapor dome;

an annular frusto-conical preheater support member mounted on saidcasing and disposed around the periphery and proximate the lower face ofsaid rotating support;

a preheater tube assembly disposed on said preheater support, saidpreheater tube assembly comprising a helical coil wound thereon to forma vertical tubular structure extending upwardly therefrom, saidpreheater tube assembly peripherally enclosing the tubular structureformed by said vapor tubes, means to supply fluid to said preheater coilfor preheating therein, and means connecting said preheater tubeassembly to said reservoir for transmitting the preheated fluid fromsaid preheater tube assembly to said reservoir;

and means to control the quantity of liquid supplied to said preheatertube assembly, said means being actuated by the location of thevapor-liquid interface between said vapor tube assembly and saidsuperheater tube assembly.

18. A vapor generator in accordance withclaim 17 wherein said means tocontrol communication with said standpipe comprises:

a valve seat concentrically disposed at the top of said standpipe;

a valving member movable with respect to said seat between a closedposition engaging said seat blocking communication with said standpipeand an open position spaced from said seat and providing communicationbetween said dome and said standpipe;

a cylinder coaxially disposed over said valve seat, said cylinder havinga closed end and open end thereto, said open end being disposed adjacentsaid valve seat;

a follower piston associated with said valving member and movabletherewith, said piston having transverse areas on either side thereof,said piston being slidably mounted in said cylinder and having atransverse area thereof exposed to the interior of said dome, saidpiston further having a transverse area exposed to the interior of saidcylinder greater than the transverse area thereof exposed to theinterior of said dome, partial sealing means between said dome and saidcylinder to provide a control leakage between the interior of said domeand said cylinder;

bleed means including a bleed valve disposed on the exterior of saidenclosure and communicative with the interior of said cylinder toprovide remote control of bleeding from the interior of said cylinder;whereby closure of said bleed valve provides actuation of said pistonand said valving member to said closed position under the influence ofdifferential pressure for acting on said piston resulting from thepressure buildup in said cylinder through leakage thereto from saiddome, and whereby opening of said bleed valve will provide actuation ofsaid valving member to said open position under the influence of adiflerential pressure acting on said piston resulting from the drop inpressure in said cylinder through the loss of pressure therefrom throughsaid bleed valve. 19. A vapor generator in accordance with claim 17wherein said sealing means comprises an annular nonrotating shoulderhaving a transverse surface thereto coaxially mounted on said annularwall, said shoulder having a cylindrical sealing surface therearound, anannular non-rotating sealing member slidably and sealably mounted onsaid sealing surface, a rotating shoulder mounted on said rotatingsupport in opposed coaxial spaced relationship to said non-rotatingshoulder, said rotating shoulder having a cylindrical sealing surfacetherearound and a transverse surface thereto substantially equal in areaand diameter to the transverse surface of said non-rotating shoulder, anannular rotating sealing member slidably and sealably mounted aroundsaid rotating shoulder cylindrical sealing surface in abutting sealingrelationship to said non-rotating member, the abutting faces of saidmembers being substantially equal in area and diameter to the transversesurfaces of said shoulders, said annular wall having a bore coaxiallydisposed therein defining a chamber around said shoulders and saidsealing members, annular bearings coaxially disposed around said annularwall to rotatably support said rotating support, means to providecommunication between said bearings and said chamber, means to supplylubricant under pressure to said bearings and said chamber, and means tosubstantially equalize the pressure between the lubricant in saidchamber and the fluid in said reservoir to minimize pressuredifferentials across the sealing faces of said sealing members, andmeans to bias said sealing members in sealing relation to one another.

References Cited by the Examiner UNITED STATES PATENTS 3/1905 Brown12211 4/1939 Vorkauf 39.18

1. A VAPOR GENERATOR COMPRISING: A VAPOR GENERATOR ENCLOSURE HAVINGVAPORIZABLE FLUID THEREIN, A VAPOR EXHAUST STANDPIPE DISPOSED IN SAIDENCLOSURE, MEANS TO CONTROL FLUID COMMUNICATION BETWEEN SAID ENCLOSUREAND SAID STANDPIPE, MEANS TO HEAT SAID ENCLOSURE TO PROVIDE VAPORIZATIONOF THE FLUID THEREIN, A ROTATING SUPPORT IN SAID ENCLOSURE COAXIALLYDISPOSED INTERMDIATE THE ENDS OF SAID STANDPIPE, A VAPOR DOME MOUNTED ONSAID ROTATING SUPPORT TO ENCLOSE THE UPPER END OF SAID STANDPIPE, AFLUID HEAT EXCHANGE AND TRANSMITTING TUBE ASSEMBLY DISPOSED ON SAIDROTATING SUPPORT, MEAN TO TRANSMIT VAPOR FROM SAID ASSEMBLY TO SAIDVAPOR DOME FOR STORAGE THEREIN A PREHEATER TUBE ASSEMBLY FIXEDLY MOUNTEDAROUND THE WALLS OF SAID ENCLOSURE ADJACENT SAID ROTATING SUPPORT ANDFLUID TUBE ASSEMBLY, MEANS TO SUPPLY LIQUID TO SAID PREHEATER TUBEASSEMBLY FOR PREHEATING THEREIN AND MEANS TO TRANSMIT PREHEATED LIQUIDTHEREFROM TO THE FLUID TUBE ASSEMBLY DISPOSED ON SAID ROTATING SUPPORT,AND MEANS TO CONTROL THE QUANTITY OF LIQUID AND HEAT SUPPLIED TO SAIDGENERATOR.